Driving under the influence of drugs in the Netherlands: Toxicological results between 2017 and 2023

This study evaluates the presence of drugs of abuse (DOA) in blood from drivers suspected of driving under the influence of drugs (DUID) in the Netherlands from 2017 to 2023. After the introduction of new Dutch DUID legislation in July 2017, police officers were provided roadside oral fluid drug testers to establish suspicion of DUID. Since, there has been a steady and continuing increase in the number of apprehended DUID drivers. A large set of 64,116 blood samples was analysed for the following DOA: cocaine, THC, morphine, GHB and Amphetamine Type Substances (ATS: amphetamine, methamphetamine, MDMA, MDA, and MDEA), and compared with the Dutch legal limits. Most of the apprehended drivers were men (92 %), with a median age of 29 years. Of the analyzed blood samples, 65 % was found positive for one or more DOA. The most prevalent drug was THC (71 %), followed by amphetamine type substances (ATS, 30 %), cocaine (15 %) and GHB (6.8 %). Poly-drug use was found in 14 % of the samples, main combinations being THC with amphetamine or cocaine, and GHB with amphetamine. Factors contributing to negative blood results are, amongst others, the blood-oral fluid ratio, a time delay between oral fluid testing and blood sample collection and sending in samples despite a negative oral fluid test. THC was more common amongst younger drivers (under 26 years old), whereas cocaine and ATS use increased with age. The study presents important knowledge for both policymakers and DUID prevention specialists.